The long term objective of this project is to improve transfusion safety for anemic premature infants by using stored autologous placental blood instead of adult donors as t he source of red cells needed for transfusion. Specific aims include 1) determining the feasibility of harvesting placental blood, 2) eliminating the problem of bacterial contamination during harvesting, 3) defining the effect of storage in vitro on fetal red cells. 4) measuring the lifespan of stored fetal red cells upon reinfusion into adult on neonatal recipients, and 5) determining the effect of transfusion of fetal r ed cells on oxygen transport in neonatal recipients. We will harvest placental blood under strict antiseptic conditions from premature infants (gestational age lesser than 33 wks) and measure the volume obtained and whether bacterial contamination occurs. Two approaches to eliminating bacterial contamination will be tested: leukofiltration and decontamination with newly developed compounds used in conjunction with red light to inactivate pathogens. To see whether the red cells of premature infants are stable during storage at 4 degrees, CPD-A anticoagulated placental blood will be stored in plastic bag s and sampled at weekly intervals for measurements of red cell metabolites, oxygen affinity, Na, K, morphology, deformability, density, vesiculation, and oxidative damage as well as supernatant hemoglobin and pH. Since irradiation of placental blood will probably be necessary to eliminate any change of contaminating maternal lymphocytes causing graft vs host disease, adverse effects of irradiation (2500cGy) on fatal red cells will be sought, using the measurements described for stored cells. The survival of stored fetal red cells after reinfusion will be measured using a nonradioactive label (biotin) and, in some instances in adult recipients the standard radiolabel (Cr51). Finally, the effect of fetal red cells on oxygen transport will be evaluated in premature infants who require a transfusion by measurements of oxygen consumption (using a metabolic gas monitor), available oxygen, heart rate, and blood lactate level before and after transfusion.